There is no way to do that exact thing on the Mark 1, as there isn't a separate control line for the power antenna.

The Mark 2 has that ability, so I guess the real answer to your question is "buy a mark 2".

For the mark 1, most people tie their antenna control into the amplifier remote activation wire. This powers your antenna whenever the player is powered up at all. It's not exactly the same thing, but it's close.